1. Field of the Invention and Related Art Statement
The present invention relates to an endoscope apparatus for use in biopsy for diagnosing insides of cavities. In general, the endoscope apparatus comprises an inserting portion to be inserted in a cavity under the inspection and having distal and proximal ends, a subsidiary operating portion having one end connected to the proximal end of the inserting portion, and a primary operating portion having one end connected to the other end of the subsidiary operating portion.
Various kinds of endoscopes for use in diagnosis or biopsy have been suggested. For example, Japanese Patent Laid-open Publication Kokai Sho No. 60-227,740 discloses an endoscope apparatus in which an ultrasonic vibrating element for transmitting and receiving ultrasonic waves is provided at the distal end portion of a flexible inserting portion, a flexible driving shaft is extended through the inserting portion from the ultrasonic vibrating element up to a subsidiary operating portion, which is connected to the lower portion of a primary operating portion, a driving means is provided in the subsidiary operating portion and the driving power generated thereby is transmitted to the ultrasonic vibrating element via the driving shaft to effect the mechanical scanning for the cavity, a forceps channel is also extended through the inserting portion, and all kinds of forceps are inserted therethrough from an opening formed in the primary operating portion to conduct treatments of biopsy such as collection of living tissues.
However, in such conventional endoscope apparatus, the forceps channel is arranged to be extended from the distal end of the inserting portion to the primary operating portion, so that the forceps opening should be formed in the primary operating portion, and all kinds of forceps have to pass through the subsidiary operating portion arranged between the primary operating portion and the proximal end of the inserting portion. In the subsidiary operating portion, there are arranged a motor for rotating the ultrasonic vibrating element, a device for detecting the rotation of the motor, etc. Therefore, the forceps channel has to be provided in the subsidiary operating portion such that the channel does not interfere with various components. Thus, there is a problem that the forceps can not travel in the forceps channel so smoothly.
Further, the length of the forceps for endoscopes has a general standard. There is also a problem in that it is necessary to use the special long forceps having its length longer than the standard length.
In ultrasonic endoscopes, there has been suggested an apparatus having a balloon at the distal end of the inserting portion. In this apparatus, when diagnosis is conducted, a liquid is supplied into the balloon so that the ultrasonic wave is effectively propagated therethrough.
U.S. Pat. No. 4,433,692 and German Patent Laid-open Publication No. 3716963 disclose ultrasonic diagnostic apparatuses in which the ultrasonic vibrating element is provided at the distal end of the inserting portion and the head of the inserting portion is covered with a balloon. When diagnosis is conducted, the balloon is filled with an ultrasonic wave propagating liquid medium so that the outer surface of the balloon is urged against the inner wall of the cavity. Thus the ultrasonic wave is not so attenuated when it propagates in the medium so that the ultrasonic diagnosis can be carried out effectively. In order to operate the apparatus effectively, the ultrasonic propagating liquid medium has to be supplied to and exhausted from the balloon smoothly. In the ultrasonic diagnostic apparatus, it is also required to provide a suction device for sucking and removing obstacles existing in the cavity through a suction channel connected to the device. Therefore, in the ultrasonic diagnostic apparatus, there is a necessity to provide two suction means one of which is for sucking the liquid in the balloon and the other of which is for sucking the obstacles in the cavity. In Japanese Patent Laid-open Publication Kokai Sho No. 58-65,129, these two suction devices are integrated to one device, so that the operating efficiency is increased.
Heretofore, the ultrasonic endoscope in which the suction channel for sucking obstacles in the cavity is commonly used as the forceps channel is desired and practiced. In such endoscope, the forceps are inserted through the suction channel to effect the endoscopic treatment, for example biopsy for the tissues of the cavity.
However, at the distal end of the inserting portion of the conventional ultrasonic diagnostic apparatus having the balloon, if the suction channel is commonly used with the forceps channel, there would be problems as follows. That is to say, in case the liquid in the balloon is exhausted and the obstacles in the cavity are sucked by only one suction device, since the switching device of said suction device is located closer to the inserting portion than the position of the forceps opening, the forceps have to travel through the switching device to the distal end of the inserting portion. Thus, the forceps are sometimes obstructed from being inserted in the channel smoothly. In accordance with the position of the switching device, the forceps could not be inserted. Also, there is another problem in that when the forceps is inserted in the channel, the liquid in the balloon cannot be sucked therefrom.